The man who spent the last years of his life fighting in vain to save Herbie, the oldest known American elm tree in New England, made his living in the forestry business, clearing and selling trees across southern Maine.

Yet Knight, who died Monday at the age of 103, valued trees for their natural beauty and spent more than 50 years protecting the town’s street trees as Yarmouth’s volunteer tree warden.

"He used to joke that he probably took down more trees than he saved," said Deb Hopkins, Knight’s friend and the tree warden who took his place 10 years ago.

"But he did save a lot of trees," Hopkins said. "Herbie was the apple of his eye. He was passionate about that one tree because it was so beautiful."

Knight died Monday morning in hospice care in Scarborough. A celebration of his life will be scheduled in the next few days, and Knight will be buried in a hand-crafted casket made from Herbie’s wood.

"Frank cared for Herbie for 52 years, and now Herbie will care for Frank forever," said his son, Dick Knight, who lives in North Yarmouth.

Frank Knight was a dedicated and active citizen of the town for decades before he gained national fame in 2009 for his effort to save Herbie, a 217-year-old tree that succumbed to Dutch elm disease and had to be cut down in January 2010.

Herbie took root in 1793 -- state forestry experts counted the tree’s rings -- the year George Washington began his second term as president. Under Knight’s care, Herbie survived 14 bouts of the fungal disease that decimated much of the region’s elm trees.

Oh.'In an attempt to block the fungus from spreading farther, the tree reacts by plugging its own xylem tissue with gum and tyloses, bladder-like extensions of the xylem cell wall. As the xylem (one of the two types of vascular tissue produced by the vascular cambium, the other being the phloem) delivers water and nutrients to the rest of the plant, these plugs prevent them from travelling up the trunk of the tree, eventually killing it.'Sucks